> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bolta.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Amend Tax Invoice - Cancellation of Contract

> For a "Cancellation of Contract" amendment, you pass only the single `date` (write date) field, and the original issued invoice is offset. Amendment is not possible if an item's supply cost on the original tax invoice is negative.

For details, see the [Amendment types guide](/en/api-introduction/amendment-guide).




## OpenAPI

````yaml /openapi.en.yaml post /v1/taxInvoices/{issuanceKey}/amend/termination
openapi: 3.1.0
info:
  title: Bolta API
  description: >
    The Bolta e-tax invoice API. [API Overview](/en/api-introduction/overview) |
    [Authentication guide](/en/api-introduction/authentication) | [Use
    cases](/en/api-introduction/usecase-b2b)
  version: 1.0.0
servers:
  - url: https://xapi.bolta.io
    description: Bolta API server
security:
  - basicAuth: []
tags:
  - name: Tax Invoice
    description: >
      Issue and manage e-tax invoices. [Calculating the issuance
      amount](/en/api-introduction/issuance-guide) | [Amendment
      types](/en/api-introduction/amendment-guide)
  - name: Reverse Issuance
    description: >
      Request and manage reverse issuance of e-tax invoices. [Email-approval
      reverse issuance](/en/api-introduction/usecase-reverse-email) |
      [Simple-approval reverse
      issuance](/en/api-introduction/usecase-reverse-simple)
  - name: Cash Receipt
    description: >
      Issue, cancel, and check the status of cash receipts. Issuance and
      cancellation are asynchronous. Check the final result via webhook or the
      status API. [Cash receipt guide](/en/api-introduction/cash-receipt-guide)
      | [Webhook events](/en/api-introduction/webhook-events)
  - name: Supplier
    description: >
      Register and manage the supplier (issuer) that issues tax invoices.
      [Glossary](/en/api-introduction/glossary) | [Delegated
      issuance](/en/api-introduction/usecase-delegated)
  - name: Certificate
    description: >
      Register and manage the supplier's certificate. [Authentication
      guide](/en/api-introduction/authentication)
paths:
  /v1/taxInvoices/{issuanceKey}/amend/termination:
    post:
      tags:
        - Tax Invoice
      summary: Amend Tax Invoice - Cancellation of Contract
      description: >
        For a "Cancellation of Contract" amendment, you pass only the single
        `date` (write date) field, and the original issued invoice is offset.
        Amendment is not possible if an item's supply cost on the original tax
        invoice is negative.


        For details, see the [Amendment types
        guide](/en/api-introduction/amendment-guide).
      parameters:
        - name: issuanceKey
          in: path
          description: Issuance request identifier
          required: true
          schema:
            type: string
        - name: Supplier-Key
          in: header
          description: >-
            The identification key of the supplier (issuer). This is the key of
            the issuing party itself, not the supplied party (recipient). Use
            the supplierKey obtained from the Register Supplier API (POST
            /v1/suppliers); the supplied party information goes in the supplied
            field of the request body. It is managed independently per API key.
            [Glossary](/en/api-introduction/glossary) | [Authentication
            guide](/en/api-introduction/authentication)
          required: true
          example: SupplierKey_bf8paz
          schema:
            type: string
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                date:
                  $ref: '#/components/schemas/DateString'
                  title: Write date
                  description: Contract cancellation date
              required:
                - date
      responses:
        '200':
          description: ''
          content:
            application/json:
              schema:
                type: object
                properties:
                  issuanceKey:
                    $ref: '#/components/schemas/IssuanceKey'
                    description: The IssuanceKey of the amended tax invoice
                required:
                  - issuanceKey
          headers: {}
        '400':
          description: Bad request
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '500':
          description: Internal server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
      deprecated: false
components:
  schemas:
    DateString:
      type: string
      format: date
      examples:
        - '2024-08-24'
    IssuanceKey:
      type: string
      description: >-
        An identifier for the issuance request. Note that the format and length
        may change.
      examples:
        - 8D529FAD3EBAE050B79CE943CCC7CEDE
    ErrorResponse:
      type: object
      description: The error response returned when an API request fails
      properties:
        code:
          type: string
          description: Error type identifier
        message:
          type: string
          description: Error description
      required:
        - code
        - message
  securitySchemes:
    basicAuth:
      type: http
      scheme: basic
      description: >-
        Base64-encode your API key and pass it. Enter the API key as the
        username and leave the password empty.

````